Containers from which food and other consumables are dispensed through valves are generally provided with removable dust covers that enclose the valve openings. A variety of arrangements, such as a screw thread and elastically deformed lugs, are commonly known arrangements for holding the cover in place.
Aerosol containers of the type that are conventionally used for natural and artificial whipped cream, for example, usually have a rounded top in which the valve is disposed, the valve being surrounded by a rim. The valve can be actuated by displacing a sleave laterally to an off-center position, thereby causing the contents to be expelled through the sleave. To prevent inadvertent actuation of the valve and to maintain the contents in a sanitary condition, a plastic dust cover is placed over the sleave. Lugs on the bottom edge of the cover, of which there are usually two, resiliently engage the rim in a snap-on fashion, securing the cover to the container.
It is well known to provide an actuator whereby one of the lugs of the cover can be disengaged from the rim and the cover can be removed. An arrangement of this type is shown in U.S. Pat. No. 3,927,796 to Whitehouse issued on Dec. 23, 1975.
It has been found that, with a certain amount of skill and persistence, it is possible to remove a plastic dust cover of this type without leaving any indication that the cover has been tampered with. In fact, the elasticity of the plastic permits such a cover to be deformed sufficiently to disengage the lugs from the rim without using the actuator. It is then possible to force the cover back onto the rim in the original manner, perhaps after dispensing part of the contents of the container.
An objective of the present invention is to provide an improved dust cover that cannot be removed from the container without some permanent deformation. Thus, a consumer will know that if a cover is intact and has not been removed, the container carries the same complete contents with which it was originally filled. A further objective is to provide such a cover that does not add significantly to the cost of the article and is conveniently and easily used by the consumer. A still further objective is to provide such a cover that can be readily reused by the consumer after the container has been partially emptied.